冬天撒盐，为什么能化冰？

Ice melts at zero degrees Celsius. 冰在零度会化成水。 Salt mixed with water lowers that point. 盐混进水里，会让这个温度降低。 So ice can melt even below zero. 所以零度以下，冰也能化。 The road becomes wet and not slippery. 路面变成湿的，就不滑了。 That is why workers salt icy roads. 这就是工人往冰路上撒盐的原因。 But too much salt is bad for plants. 不过盐太多，对花草也不好。